Thin and Fat Client Model

There are two type models of the client-server architecture.

Thin-client model
In a thin-client model, all of the application processing and data management is carried out on the server. The client is simply responsible for running the presentation software.

Fat-client model
In this model, the server is only responsible for data management. The software on the client implements the application logic and the interactions with the system user.



Thin CLient Model:
-Used when legacy systems are migrated to client server architectures.
-The legacy system acts as a server in its own right with a graphical interface implemented on a client.
-A major disadvantage is that it places a heavy processing load on both the server and the network.

Fat Client Model:

-More processing is delegated to the client as the application processing is locally executed.
-Most suitable for new C/S systems where the capabilities of the client system are known in advance.
-More complex than a thin client model especially for management. New versions of the application have to be installed on all clients.

Activity Diagram

Activity diagrams are used for to show a subprocess of a system by figures. Big black dot means the start and the Black dot and a circle outside it means end. Also the arrows represent yes and no answer to the process.That means if yes process done if no can not be done. The diamond are the process steps.
We still continue on the example we examined at last two articles. Here are the some examples from the dynamic web site system:

Activity diagram for use case of Adminstrator to send and receive mails.



Activity diagram for use case of all users to post messages.



Activity diagram for use case of Student to add comments.

Introduction to PHP

PHP means "Personel Home Page Tools" which invented by Rasmus Lerdorf nearly in 1995 or earlier. It is a SSS (Server Side Script) which he needs strong on database and answers to dynamic site design needs. After the expansion of PHP had became "PHP is a Hypertext Pre-Processor".If you want more detail about history of PHP take a look at http://www.php.net/manual/en/history.php .

Now let's start to understand the capablities of PHP.For me it is capable for every work :) Since it is developed more and more it is good for everything you want to do.

• You can create your own graphics by PHP.
• You can create Flash documents without any need to Flash and some kind software.
• PHP is good for interwork with every database system such as MS SQL, MySQL etc.
• And if you can not find something you need you can write it on your own and can share it.

And it is time to explain how you can use PHP now. PHP is an platform independent web language.Firstly you need to decide on which web server you will use. I recommend you Apache which is a platform dependent server as well. If you are a Windows platform user it is nice for you to use PHPTriad. It includes both Apache, MySql and PHP. Also PHPTriad is called as sokkit after its 2nd version which you can acces from http://www.sokkit.net .

After you do this wait for your PHP codes and explainings of them and wait for next article:)